The world's first Business-to-Business online shopping or e-commerce system dates back to Thomson Holidays UK 1981. The travel industry since then has remained in the forefront of e-commerce usage. E-commerce changed the travel industry.
The early Sabre and Travicom airline reservation systems were replaced by the airlines' own systems as the airlines followed the holiday tour operators. Travel today is increasingly bought direct from the provider, 24/7 on-line real-time and usually paid for at time of booking. Whether the consumer is home, at work or just mobile the full sales process is always available instantaneously - Seek travel, Find options, Compare and Select, Check availability, Book, Confirm, Pay, Provide ID info, Book add-ons - car hire, hotel, satnav etc.
A total package is consumer created. And the consumer has access to independent reference sites to check quality and provide feedback. The travel industry is an e-commerce business. Agencies still exist to provide specialist services but overall the business has been productised.